The new president of the Maldives has opened parliament amid protests by the opposition, nearly six weeks after he took office in what his predecessor has called a coup.

Police fired tear gas earlier on Monday as several hundred demonstrators blocked roads and shouted slogans calling for the resignation of President Mohammed Waheed Hassan. Waheed was prevented from opening parliament on March 1 amid protests by opposition legislators.

Hassan was vice president when he replaced Mohamed Nasheed last month after his predecessor resigned following weeks of public protests and a loss of support from the military and police.

Nasheed later claimed that he was forced to resign at gunpoint in what he called a coup. He demanded that Waheed resign immediately and call fresh elections. Waheed says the power transfer was constitutional.

Television footage on Monday showed security staff in the parliament building forcibly removing four opposition legislators as they were trying to stop Waheed from making his opening speech.

After a few hours' delay, Waheed made his speech in which he called for national unity. However, street protests continued.

In Monday's speech, Waheed said the Maldives' constitution did not allow a presidential election before July 2013 and an early election would require constitutional amendment.